[GRASS5] making raster maps from vector maps with PostgreSQL data in GRASS 5.3

[Michael Barton]

Tom,

Thanks for this suggestion.

On Friday, January 9, 2004, at 08:52  AM, Thomas Adams wrote:

> Michael,
>
> Iteresting you should ask this question since I had a similar need. 
> What you need to do is this:
>
> (1) first do the v.to.rast conversion on your vector files, creating 
> the raster equivalents
>
> (2) if you have the dig_cats files for the vector files, then simply 
> copy them into the cats directory; the only thing is that the cats 
> filenames & the cell file names must be the same - then you're done.

Actually I don't **think** that this is even necessary if you have 
dig_cats. I **think** that v.to.rast will copy the vector attributes 
into the proper raster cat & label files. The problem, of course is 
that I **don't** have the dig_cats  file and want to create it from a 
PostgreSQL table column. However, barring an elegant solution to this, 
what you recommend below will work even if it is 'brute force'. Thanks 
again.


>
> (3) if you don't have the dig_cats files, you'll have to do a SQL 
> query to dump the attributes to a text file by polygon area and then 
> do a little file manipulation to get them into the format needed for 
> Step-(2) above.
>
> Now, this may be a brute force way to do this and someone else will 
> come along with something more elegant, but it will work.
>

Michael


> Regards,
> Tom
>
>
>
> Michael Barton wrote:
>
>> Here is the setup:
>>
>> I have a vector area map with related information in a PostgreSQL 
>> database. I can query and display the vector map using information 
>> from any of the data fields in the PostgreSQL table.
>>
>> What I'd like to do is create a series of raster maps of the vectora 
>> areas in which the cat and/or label values are derived from a 
>> corresponding series of field from the PostgreSQL file (e.g., raster 
>> map1 using field 1, raster map2 using field 2, etc.)
>>
>> How do I get data from a PostgreSQL field into the cat or label field 
>> of a vector file so I can do a v.to.rast transformation?
>>
>> Or is there another solution to this?
>>
>> Thanks
>> Michael Barton
>> ______________________________
>> Michael Barton, Professor & Curator
>> Department of Anthropology
>> Arizona State University
>> Tempe, AZ  85287-2402
>> USA
>>
>> voice: 480-965-6262; fax: 480-965-7671
>>
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>
>
> -- 
> Thomas E Adams
> National Weather Service
> Ohio River Forecast Center
> 1901 South State Route 134
> Wilmington, OH 45177
>
> EMAIL:	thomas.adams at noaa.gov
>
> VOICE:	937-383-0528
> FAX:	937-383-0033
>
>
>
______________________________
Michael Barton, Professor & Curator
Department of Anthropology
Arizona State University
Tempe, AZ  85287-2402
USA

voice: 480-965-6262; fax: 480-965-7671